if (self::isUnderscoreVariableName($var_name) === false) {
                    $error = 'Variable "%s" is not in valid undercase format';
                    $data  = [$var_name];
                    $phpcs_file->addError($error, $stack_ptr, 'StringVarNotUnderscore', $data);
                } elseif (preg_match('|\d|', $var_name) === 1) {